A LINKAGE STUDY INVOLVING TWO WHEAT-RYE TRANSLOCATION CHROMOSOMES

1969 ◽  
Vol 11 (1) ◽  
pp. 143-146 ◽  
Author(s):  
C. J. Driscoll ◽  
G. D. Patil
Keyword(s):  
Genetic Markers ◽  
Transmission Rate ◽  
Wheat Chromosome ◽  
Linkage Study ◽  
Linkage Test ◽  
Crossing Over ◽  
Complete Linkage ◽  
Transmission Rates ◽  
Chromosome Arm

Two wheat-rye translocation chromosomes involving the same wheat chromosome arm but different rye segments were subjected to a linkage test. Apparently no crossing over occurred between the non-homologous rye segments. The genetic markers possessed by these rye segments showed complete linkage in repulsion. The male transmission rates of the translocation chromosomes agree with those expected on the basis of the male transmission rate of each when competing with the normal wheat chromosome.

scholarly journals Genomic Analysis of the Snn1 Locus on Wheat Chromosome Arm 1BS and the Identification of Candidate Genes

2008 ◽  
Vol 1 (1) ◽  
Author(s):  
Leela Reddy ◽  
Timothy L. Friesen ◽  
Steven W. Meinhardt ◽  
Shiaoman Chao ◽  
Justin D. Faris
Keyword(s):  
Candidate Genes ◽  
Genomic Analysis ◽  
Wheat Chromosome ◽  
Chromosome Arm

scholarly journals Reduced chromatin accessibility underlies gene expression differences in homologous chromosome arms of diploid Aegilops tauschii and hexaploid wheat

GigaScience ◽  
2020 ◽  
Vol 9 (6) ◽  
Author(s):  
Fu-Hao Lu ◽  
Neil McKenzie ◽  
Laura-Jayne Gardiner ◽  
Ming-Cheng Luo ◽  
Anthony Hall ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hexaploid Wheat ◽  
Aegilops Tauschii ◽  
Wheat Chromosome ◽  
Pilot Scale ◽  
Chromatin Accessibility ◽  
Diploid Progenitor ◽  
Genomic Changes ◽  
Chromosome Arm ◽  
Elevated Expression

Abstract Background Polyploidy is centrally important in the evolution and domestication of plants because it leads to major genomic changes, such as altered patterns of gene expression, which are thought to underlie the emergence of new traits. Despite the common occurrence of these globally altered patterns of gene expression in polyploids, the mechanisms involved are not well understood. Results Using a precisely defined framework of highly conserved syntenic genes on hexaploid wheat chromosome 3DL and its progenitor 3 L chromosome arm of diploid Aegilops tauschii, we show that 70% of these gene pairs exhibited proportionately reduced gene expression, in which expression in the hexaploid context of the 3DL genes was ∼40% of the levels observed in diploid Ae tauschii. Several genes showed elevated expression during the later stages of grain development in wheat compared with Ae tauschii. Gene sequence and methylation differences probably accounted for only a few cases of differences in gene expression. In contrast, chromosome-wide patterns of reduced chromatin accessibility of genes in the hexaploid chromosome arm compared with its diploid progenitor were correlated with both reduced gene expression and the imposition of new patterns of gene expression. Conclusions Our pilot-scale analyses show that chromatin compaction may orchestrate reduced gene expression levels in the hexaploid chromosome arm of wheat compared to its diploid progenitor chromosome arm.

scholarly journals Cytomolecular Identification of Individual Wheat-Wheat Chromosome Arm Associations in Wheat-Rye Hybrids

2013 ◽  
Vol 139 (2) ◽  
pp. 128-136 ◽  
Author(s):  
M. Megyeri ◽  
M. Molnár-Láng ◽  
I. Molnár
Keyword(s):  
Wheat Chromosome ◽  
Chromosome Arm

Factors influencing transmission of alfalfa mosaic virus through seed of annual medics (Medicago spp.) and the genetic control of seed transmission rate

1997 ◽  
Vol 48 (7) ◽  
pp. 989 ◽  
Author(s):  
W. Pathipanawat ◽  
R. A. C. Jones ◽  
K. Sivasithamparam
Keyword(s):  
Mosaic Virus ◽  
Genetic Control ◽  
Transmission Rate ◽  
Alfalfa Mosaic Virus ◽  
Seed Transmission ◽  
Virus Concentration ◽  
Rate Condition ◽  
Reciprocal Crosses ◽  
Transmission Rates ◽  
Annual Medics

Factors likely to influence rates of transmission of alfalfa mosaic virus (AMV) through seed to seedlings of annual medics (Medicago spp.) and genetic control of the magnitude of its seed transmission rate were investigated in plants from 17 early-flowering accessions of M. polymorpha and in progenies of crosses involving M. murex cv. Zodiac × accession 5320 as parents. Plants were graft-inoculated when 6 weeks old to ensure successful and uniform infection. To exclude variation in seed transmission rates due to virus isolate or temperature, only 1 AMV isolate was used and the plants were kept under uniform temperature conditions. In M. polymorpha, significant differences were found between accessions in the levels of AMV transmitted through seed to progeny seedlings, SA 8250 giving the highest mean level of seed transmission (52%) and SA 4188 the lowest (3%). Neither virus concentration nor symptom severity influenced the rates of seed transmission obtained. However, part of the variation in seed transmission rates found in these accessions was related to their flowering times, seed transmission rates increasing as the interval between inoculation and owering increased. In seed samples collected from individual graft-inoculated plants of M. murex from (i) the F2 generation from crosses and reciprocal crosses, and (ii) the backcross progenies, the rates of transmission of AMV through seed to seedlings ranged from 0 to 77% and showed a continuous pattern of variation. Also, there was evidence of transgressive segregation for the low seed transmission rate condition. This indicates that the low seed transmission rate condition for AMV in medics is quantitatively inherited and under polygenic control. In contrast, when the pods from F2 progeny plants from the crosses and reciprocal crosses were examined, the segregation ratios obtained revealed that the smooth pod character from parent accession 5320 was controlled by a single recessive gene, for which the name sp is proposed. The presence in a plant of gene sp, or of its spiny pod-determining allele from the other parent cv. Zodiac, was not correlated with low seed transmission rates of AMV. It is concluded that selection for low rates of seed transmission and a population breeding approach can be used to produce improved M. polymorpha and M. murex cultivars with good resistance to seed-borne AMV

FERTILITY COMPENSATION OF CORNERSTONE MALE STERILITY OF WHEAT BY RYE

Genetics ◽  
1983 ◽  
Vol 104 (1) ◽  
pp. 181-189
Author(s):  
M A Hossain ◽  
C J Driscoll
Keyword(s):  
Male Sterility ◽  
Male Fertility ◽  
Wheat Chromosome ◽  
Hybrid Wheat ◽  
Specific Expression ◽  
Entire Chromosome ◽  
Chromosome Arm ◽  
Fertility Gene

ABSTRACT The genome of rye is known to compensate for the lost male-fertility gene(s) of wheat chromosome arm 4Aα in the Cornerstone male-sterility mutant. A search for the rye chromosome(s) involved in this compensation showed that chromosomes 2R and 4R are responsible. Only the short arms of these two chromosomes are the operative ones. Chromosome arm 4RS compensates in an erratic way, whereas 2RS compensates in a full and consistent way. The entire chromosome 2R compensates less well than the 2RS telocentric which reflects an antifertility factor(s) on 2RL. This may be a specific expression of the 2R genes for poor vigor which are located on only the long arm. 2RS will be a valuable piece of chromatin for the XYZ system of producing hybrid wheat.

scholarly journals Modeling the Novel Coronavirus (SARS-CoV-2) Outbreak in Sicily, Italy

2020 ◽  
Vol 17 (14) ◽  
pp. 4964 ◽  
Author(s):  
Andrea Maugeri ◽  
Martina Barchitta ◽  
Sebastiano Battiato ◽  
Antonella Agodi
Keyword(s):  
Transmission Rate ◽  
Control Measures ◽  
Transmission Dynamics ◽  
The Novel ◽  
Epidemic Spread ◽  
Transmission Rates ◽  
Contact Precautions ◽  
Travel Restrictions ◽  
Novel Coronavirus ◽  
Reported Data

Italy was the first country in Europe which imposed control measures of travel restrictions, quarantine and contact precautions to tackle the epidemic spread of the novel coronavirus (SARS-CoV-2) in all its regions. While such efforts are still ongoing, uncertainties regarding SARS-CoV-2 transmissibility and ascertainment of cases make it difficult to evaluate the effectiveness of restrictions. Here, we employed a Susceptible-Exposed-Infectious-Recovered-Dead (SEIRD) model to assess SARS-CoV-2 transmission dynamics, working on the number of reported patients in intensive care unit (ICU) and deaths in Sicily (Italy), from 24 February to 13 April. Overall, we obtained a good fit between estimated and reported data, with a fraction of unreported SARS-CoV-2 cases (18.4%; 95%CI = 0–34.0%) before 10 March lockdown. Interestingly, we estimated that transmission rate in the community was reduced by 32% (95%CI = 23–42%) after the first set of restrictions, and by 80% (95%CI = 70–89%) after those adopted on 23 March. Thus, our estimates delineated the characteristics of SARS-CoV2 epidemic before restrictions taking into account unreported data. Moreover, our findings suggested that transmission rates were reduced after the adoption of control measures. However, we cannot evaluate whether part of this reduction might be attributable to other unmeasured factors, and hence further research and more accurate data are needed to understand the extent to which restrictions contributed to the epidemic control.

Comparative physical mapping between wheat chromosome arm 2BL and rice chromosome 4

Genetica ◽  
2010 ◽  
Vol 138 (11-12) ◽  
pp. 1277-1296 ◽  
Author(s):  
Tong Geon Lee ◽  
Yong Jin Lee ◽  
Dae Yeon Kim ◽  
Yong Weon Seo
Keyword(s):  
Physical Mapping ◽  
Rice Chromosome ◽  
Wheat Chromosome ◽  
Chromosome 4 ◽  
Chromosome Arm

Analysis of genomic DNA copy number alterations in chromosome arm 18q demonstrates distinct molecular categories of colorectal carcinoma

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 10005-10005
Author(s):  
H. Ji ◽  
M. Zhang ◽  
K. Farnam ◽  
K. Salari ◽  
R. Davis ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Colorectal Carcinoma ◽  
Genomic Instability ◽  
Genetic Markers ◽  
New Technologies ◽  
Stage Ii ◽  
Cancer Genes ◽  
Genomic Deletions ◽  
Chromosome Arm ◽  
Dna Copy Number Alterations

10005 Background: Genomic instability is a major feature of neoplastic development in colorectal carcinoma and other cancers. Specific genomic instability events such as genomic deletions have potential utility as biologically relevant prognostic biomarkers. Loss of heterozygosity (LOH) on chromosome arm 18q is an indicator of colorectal carcinoma behavior and potentially, prognosis. For stage II and III colorectal cancer, a number of retrospective studies have shown strong correlations between deletions in 18q and reduced survival. However, other studies have failed to identify this correlation. This discrepancy is likely the result of different sets of genetic markers and their widely disparate locations along chromosome arm 18q, often separated by megabases. New technologies are needed to overcome these issues. Methods: Using a novel genomic technology called molecular inversion probes (MIPs), we analyzed genomic deletions at exon-level resolution in primary colorectal carcinoma. Unlike microsatellite genetic markers, MIPs are not dependent on having informative alleles to discern a LOH event. This enables querying microsatellite genetic markers used in any clinical study. We designed a set of probes to interrogate several hundred individual exons of over two hundred cancer genes with an overall distribution covering all chromosome arms. Also represented were a series of over 100 probes along chromosome arm 18q representing genetic markers used in clinical studies. An analysis was carried out on primary tumor samples from patients with stage II and III disease. Results: We discovered several distinct categories of colorectal carcinomas based upon their profile of 18q genomic deletions and other allelic imbalances. Colorectal carcinoma extent of invasion showed an association with cluster designation which suggests that the multiple genomic instability events influence the invasive behavior of colorectal carcinoma. Conclusions: Colorectal cancer has distinct patterns of 18q genomic deletions, representing a potential molecular classifier. This finding has potential clinical ramifications given the application of 18q LOH events as an indicator for adjuvant treatment in stage II colorectal carcinoma. No significant financial relationships to disclose.

High resolution map around the vrs1 locus controlling two- and six-rowed spike in barley, Hordeum vulgare

Genome ◽  
1999 ◽  
Vol 42 (2) ◽  
pp. 248-253 ◽  
Author(s):  
Takao Komatsuda ◽  
Wenbin Li ◽  
Fumio Takaiwa ◽  
Seibi Oka
Keyword(s):  
Hordeum Vulgare ◽  
Mapping Population ◽  
Recombination Frequency ◽  
Linkage Study ◽  
Linkage Data ◽  
Published Data ◽  
Crossing Over ◽  
Lateral Spikelet ◽  
Significant Difference ◽  
High Resolution Map

The vrs1 (formerly v) locus in the long arm of chromosome 2H controls lateral spikelet development in barley. The vrs1 locus was mapped by backcross-derived lines that consisted of 373 BC7F1 plants and 278 BC6F2 plants. The linkage study indicated that MWG801, CMNA-38/700, cMWG699, vrs1 and MWG865 exist in the order listed, with map distances of 3.1, 0.4, 0.1, and 0.9 centimorgans (cM), respectively. Recombination in female and male meiocytes showed no significant difference within this region. In a neighboring region between MWG865 and MWG503, the recombination frequency was higher in female than male meiocytes in one mapping population. The combined linkage data obtained from this study were compared with published data, and genotype-specific suppression of crossing-over was not evident in the vrs1 region.Key words: vrs1 locus (two- vs. six-rowed), molecular marker, recombination, backcross, Hordeum vulgare.

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